Controlling Log Carriage Knees

Hello, I want a bit of advise as to the best way to control the knees on a log carriage using a RMC150E. I don’t have any problems with making the knees move but run into a couple of issues when jogging the knees in and out and disabling knees and want to know the best way of dealing with it.

the first problem is if the operator is tapering the knees. The best way to do this is to sync the axis then start the move to target positions that have been calculated. Where I run into problems is that the operator may have been jogging the knees as he started to taper, to be able to sync them they need to be stopped according to the help but for the opeation of the carriage it is not practical to stop the knees first. The next problem I have is if he is tapering in, he may want to taper out before the knees have stopped, do I have to wait for the knees to stop, when I see them stop in the PLC issue the sync move command in the other direction???

The next problem I have is if a knee is disabled (short logs, or a broken knee). How do I get around this. Do i have to have a program for every combination of knees that are enabled??? There are 4 knees on the carriage, there could be a lot of combinations…

I have done the same job using a RMC100, I did not have these problems because I could set in the command word for each knee if it was in a particular sync group, and it did not seem to have any problems with changing directions, sync’ing while moving etc. Am I better to get a RMC100 instead??? I assume that someone would have used an RMC150E on a log carriage before.


Greg Shiels
Tui Technology